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• MPEG DASH SRD : How to properly re-assemble multiple tiles into a single tile [closed]

  21 juin 2024, par ATrashInTheWorld

  I am trying to build a web player that is able to stream MPEG DASH, but with SRD information in the manifest. I have a problem at the "gluing" of the tiles part.

  


  How the data is set :

  


  I have a video of a resolution of XxY, which I've divided in tiles of NxM, meaning that I now have the NxM videos of the same duration as the original one, but which is reduced to a smaller resolution, a portion from the original (seeing only the upper left corner for example).

  


  I have fragmented those tiles for the MPEG DASH streaming format, meaning an init.mp4 and the m4s fragments for each tile. To note that I have the tiles in multiple bitrate, in order to imitate some adaptive streaming.

  


  The "gluing" part :

  


  The gluing part consists of gluing the tile togheter into 1 big tile, aka the original video. The SRD information allows me to know where each tile should be position to reconstruct the original video shape. Once I have the spatial information from the manifest, I use this command to glue the tiles togheter :

  


  ffmpeg.exe -i v1 -i v2 -i v3 -i .v4 -i v5 -i v6 -i v7 -i v8 -i v9 -filter_complex "[0:v][1:v][2:v][3:v][4:v][5:v][6:v][7:v][8:v]xstack=inputs=9:layout=0_0|w0_0|w0+w1_0|0_h0|w3_h0|w3+w4_h0|0_h0+h3|w6_h0+h3|w6+w7_h0+h3" out.mp4


  


  The command above allows me to "glue" together tiles from a grid of 3x3 tiles, into 1 big tile.

  


  The web streaming method :

  


  To stream, I use JavaScript MediaSource, and I am appending the fragments to the buffer continuously, like this reference

  


  The issue :

  


  The issue is that the FFMPEG gluing command only works on proper mp4 videos, not with fragments (m4s). I cannot glue the wanted m4s tiles back into a bigger one. However, the JavaScript player only takes fragments, meaning that I cannot just send continuous mp4 video.

  


  I have tried many things with fragments and full videos, but the only solution I found for this chicken-egg problem is to :

  


  

  1. Create video clips with smaller duration for each tile, at each bitrate.

  


  2. Glue the desired video clips tiles together with the FFMpeg command.

  


  3. Convert that glued video in one big fragment, and send it.

  


  


  However, I feel that it is not a clean method and I fear that I am missing something.
Is there a better solution that I am not aware of ?
Any idea suggestions are welcome.

  


  Thank you for your time.

  


• Mpeg Dash code having compilation issues and want to know what to do after the code is built and how to play the .mpd file generated

  11 avril 2013, par niuuuu

  I'm trying to build the DashEncoder code which I downloaded from github https://github.com/slederer/DASHEncoder. Well, I followed all the instructions given in the how to compile dash file. installed Gpac n X264 and compiled both successfully. Then did make of Dashencoder and ran it as ./Dashencoder. But I found some issues in it. Got this log :

  ==========DASH ENCODER===============
  
  Unknown option in resourcefile : sql-pw :
  
  current encoder x264
  
  YES
  
  x264 encoding @ 300 kbps: Pass 1 
  
  x264: x264 --profile baseline --preset slow --verbose --fps 24 --vbv-maxrate 300 --vbv-bufsize 600 --scenecut 0 --keyint 48 --output /opt/lampp/htdocs/tests_updates/sintel_trailer_2k_480p24_300kbit.h264 /home/niu/sintel_trailer_2k_480p24.y4m >out.txt 2>&1 
  
  mkdir: cannot create directory `/opt/lampp/htdocs/tests_updates/sintel_300kbit': File exists
  
  cp: omitting directory `/opt/lampp/htdocs/tests_updates/'
  
  copy audio: cp /opt/lampp/htdocs/tests_updates/ /opt/lampp/htdocs/tests_updates/sintel_300kbit/MP4Box multiplexing Video: /opt/lampp/htdocs/tests_updates/sintel_300kbit/sintel_trailer_2k_480p24_300kbit.h264  
  
  mp4box: MP4Box -add /opt/lampp/htdocs/tests_updates/sintel_300kbit/sintel_trailer_2k_480p24_300kbit.h264  /opt/lampp/htdocs/tests_updates/sintel_300kbit/sintel_trailer_2k_480p24_300kbit.mp4
  
  AVC-H264 import - frame size 854 x 480 at 24.000 FPS
  
  AVC Import results: 1253 samples - Slices: 27 I 1226 P 0 B - 1 SEI - 27 IDR
  
  Saving to /opt/lampp/htdocs/tests_updates/sintel_300kbit/sintel_trailer_2k_480p24_300kbit.mp4: 0.500 secs Interleaving
  
  MP4Box multiplexing Audio:/opt/lampp/htdocs/tests_updates/sintel_300kbit/ 
  
  mp4box: MP4Box -add /opt/lampp/htdocs/tests_updates/sintel_300kbit/ /opt/lampp/htdocs/tests_updates/sintel_300kbit/sintel_trailer_2k_480p24_300kbit.mp4
  
  Unknown input file type
  
  Unknown input file type
  
  Error importing /opt/lampp/htdocs/tests_updates/sintel_300kbit/: Bad Parameter
  
  MP4Box Cleaning ... 
  
  mp4box: MP4Box -no-sys  /opt/lampp/htdocs/tests_updates/sintel_300kbit/sintel_trailer_2k_480p24_300kbit.mp4
  
  Saving /opt/lampp/htdocs/tests_updates/sintel_300kbit/sintel_trailer_2k_480p24_300kbit.mp4: 0.500 secs Interleaving
  
  MP4Box segmentation: /opt/lampp/htdocs/tests_updates/sintel_300kbit/sintel_trailer_2k_480p24_300kbit.h264  
  
  mp4box: MP4Box -frag 2000 -dash 2000 -rap -segment-name /opt/lampp/htdocs/tests_updates/sintel_300kbit/sintel /opt/lampp/htdocs/tests_updates/sintel_300kbit/sintel_trailer_2k_480p24_300kbit.mp4
  
  DASH-ing file: 2.00s segments 2.00s fragments single sidx per segment
  
  Spliting segments at GOP boundaries
  
  [DASH] Generating MPD at time 2013-03-16T16:40:03Z
  
  DASHing file /opt/lampp/htdocs/tests_updates/sintel_300kbit/sintel_trailer_2k_480p24_300kbit.mp4
  
  terminate called after throwing an instance of 'std::out_of_range'
  
    what():  basic_string::substr
  
  Error: Unable to open MPD file!Aborted

  Why is this error at the end ?
  and also one folder got created in my /opt/lampp/htdocs/tests_updates/sintel_300kbit.
  which has two types of files :
  27 files of .m4s extension
  1 file -sintelinit.mp4
  1 file- sintel_trailer_2k_480p24_300kbit.mp4 , which when played in vlc player played the video bt no audio ! &

  1 file- sintel_trailer_2k_480p24_300kbit.h264 which cannot be opened.

  No .mpd file was created.

  Also I want to know aft creating that .mpd file how will i be able to test it on my android client say media player.

  I am damn confused with all this happening. Please help.

• How to load my local mpd(mpeg-dash) file to online players ?

  18 août 2023, par Walter

  I am trying to use some online players to test my local mpd file, but it could't be loaded as 'file :///path-to-file' form like local urls, what's the correct format to load the file ? Or should I upload it online or so ?